The capability of the synthesized heteropoly complexes of rare earths {K10 [(O39W11Si) Ln(Gly)3Ln(SiW11O39)]·9H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was studied. The results showed that the quantity of H2SO4 used for synthesizing the ethyl acetate can be reduced by 75% and the yield reached 98% at the optional condition.